The men were the trusted lieutenants of British Al Qaeda "General" Dhiren Barot.

The 34-year-old Londoner was jailed for a minimum of 40 years in a previous trial – although this was reduced to 30 years on appeal.

But the latest proceedings at Woolwich Crown Court in South London provided for the first time a chilling insight into how members of his cell were hand-picked to cause maximum carnage.

Among their potential targets in the U.S. were the Empire State Building, the Chrysler Building and the New York Stock Exchange.

Targets in Britain included the Heathrow Express, three London rail stations and several hotels. The gang also hoped to build a radioactive "dirty bomb".

Unlike other Al Qaeda cells in Britain who were drawn together in a haphazard way, Barot's men were each chosen for their specific skills.

It was, said one investigator, like the film Ocean's Eleven – where each man was brought in for his different expertise. "But this was very real," he added.

Zia Ul Haq, 28, was the "consultant". He had a degree in construction management, worked for a London firm of chartered surveyors and advised Barot on where explosives should be placed to collapse buildings. Mohammed Naveed Bhatti, 27, had a Masters degree in engineering and helped draft the plans for a dirty bomb.

Junade Feroze, 31, who had attended the Finsbury Park sermons of radical cleric Abu Hamza, worked in his family's garage business. He was able to obtain the gas canisters and tyres needed for the attacks without arousing suspicion. He also acted as Barot's chauffeur and countersurveillance specialist.

Abdul Aziz Jalil, 34, rented Barot's "safe house" in London and provided false identities, money and the codes used to send messages.

He was also Barot's minder. Omar Rehman, 23, took a job at the Ramada Hotel in Watford to research into "defeating or disabling security and fire detection systems".

Qaisar Shaffi, 28, helped to carry out reconnaissance with Barot for attacks abroad.

Nadeem Tarmohamed, 29, also carried out reconnaissance in the U.S. and concealed plans for the attacks.

All apart from Shaffi pleaded guilty to conspiracy to cause explosions and the jury found Shaffi guilty of the charges and conspiracy to murder.

The court heard that Barot had gone to Pakistan in 2004 seeking backing for his plans from Al Qaeda.

Johnathan Laidlaw, prosecuting, said that while Barot "lived in the shadows" to plan the attacks, he needed the help "of those who could provide him with accommodation, false identities, professional expertise, access to false bank accounts".

Passing sentence, Mr Justice Butterfield said yesterday: "Barot was the instigator of this terrorist planning, he was by some considerable distance the principal participant in the conspiracy.

"Each one of you was recruited by Barot and assisted him at his request.

"Anyone who chooses to participate in such a plan . . . will receive little sympathy from the courts."

The judge told the defendants the suffering their families would experience "is but a tiny fraction of the suffering that would have been experienced had your plans been translated into reality". Outside court, Deputy Assistant Commissioner Peter Clarke, head of Counter-Terrorism Command, said: "The plans for a series of co- ordinated attacks in the United Kingdom included packing three limousines with gas cylinders and explosives before setting them off in underground car parks.

"This could have caused huge loss of life. The plans to set off a dirty bomb in this country would have caused fear, panic and widespread disruption."

Home Secretary John Reid added: "The outcome of this trial once again shows the extent of the very real and serious threat the UK faces from terrorism.

"Seven of the eight individuals associated with this chilling plot pleaded guilty. Their goal was mass murder, mass panic and utter devastation."

Muslim convert Barot, who was described at his trial as a "determined and experienced terrorist", was arrested in Kingsbury, North-West London, a month after his plans were found on a laptop computer seized during a July 2004 raid on a house in Gujrat, Pakistan.

His cell members were then captured in a series of coordinated raids across England.

In papers seized by police, Barot wrote: "Imagine the chaos that would be caused if a powerful explosion was to rip through London and actually rupture the river itself.

"That would cause pandemonium, what with the explosions, flooding, drowning etc that would occur."

Feroze, from Blackburn, was jailed for 22 years and Jalil, from Luton, for 26 years.

Bhatti, from Harrow, North-West London and Tarmohamed, from Willesden, North-West London, were jailed for 20 years each.

Ul Haq, from Paddington, West London, was given 18 years; Rehman, from Bushey, Hertfordshire, and Shaffi, also from Willesden, 15 years each.